The present invention relates to a parallel management system (data structure construction, use start/end, state display, data structure check, and data structure recovery) for a file data storage structure in managing data in a computer system, and, more particularly, a parallel management system for a file data storage structure in which an improvement of the speed of operations on a file data storage structure with a large capacity composed of a plurality of secondary storage devices is made by parallel processing.
An operating system (OS) typically used for a current computer system is arranged to divided a storage area in one secondary storage device into a plurality of logical storage areas each of which acts as an independent storage area into or from which data can be written or read. Each such logical storage area is called a file. The secondary storage area can be flexibly managed by increasing or decreasing the capacity of each file as long as the total capacity of all files on one secondary storage device does not exceed the storage capacity of the secondary storage device. To make possible such flexible management of the secondary storage area, a file management of an ordinary OS constructs on one secondary storage device a data storage structure (typically called a "file system") for managing files. Since the data storage structure is constructed on one secondary storage device, the capacity of each file cannot exceed the capacity of this secondary storage device, and performance accessing a file cannot exceed the performance one secondary storage device has.
A striping area assignment scheme disclosed in Japanese Patent Application Laid-Open No. 3-259320, or a file data multiplex method and a data processing system disclosed in Japanese Patent Application Laid-Open No. 6-332625 assigns the storage area for a file to a plurality of secondary storage devices, and causes one processor to manage a data structure.
Referring to FIG. 37, in such system, a plurality of secondary storage devices can be viewed as one secondary storage device, so that an application reading and/or writing data can be handled as though only one storage device is enhanced for its capacity. In addition, increasing the number of secondary storage device allows it to easily increase the capacity of file data storage structures, and to dramatically increase the capacity of secondary storage device. However, since the capacity of secondary storage device subject to the file data storage structure also becomes huge, processing time is dramatically increased for the management operation. For example, when it is intended to construct a data structure for a file data storage structure, it is necessary to prepare control data for a data structure to the capacity of secondary storage device, and to write the prepared control data on the secondary storage device. Since, if the capacity is increased for the secondary storage device, amount of control data to be prepared is also increased accordingly, amount of processing in constructing the data structure increases in proportional to the capacity of secondary storage device. Since the conventional system constructs a data structure with one processor, it requires a very long processing time when it constructs a data structure on a huge secondary storage device. Similarly, a very long time is necessary for checking a data structure of the file data storage structure and processing recovery of a data structure in proportional to increase of the capacity of secondary storage device. Thus, there have existed problems in the prior art such that, as the capacity is being increased for a file data storage structure, amount of processing and I/O increases in construction, checking, or recovery of a data structure for the file data storage structure in proportional to the capacity of file data storage structure, thereby the processing time being lengthened.